Acorn - Slipper Sock Cotton (Grey Cotton Twist) - Men's: The famous Acorn original that has been comforting the feet of astronauts since 1982. Cotton twist uppers of 93% hypoallergenic cotton and 7% spandex. Lofty Acorn memory foam midsole over comfort cushion layer of featherweight EVA guarantees total comfort and therapy for feet. Full grain leather sidewall and suede leather outsole for durable comfort. Hand wash cold; air dry.